Fix false-positives from target-specific optional features

.github/workflows/ci.yml

@@ -22,6 +22,7 @@ jobs:
       - run-on-rust-libp2p
       - run-on-libp2p-dcutr-relay
       - run-on-libp2p-gossipsub-request-response
+      - run-on-libp2p-uds
       - run-on-core-graphics
       - run-on-bevy-core
       - run-on-bevy-gltf
@@ -235,6 +236,43 @@ jobs:
       - name: Run semver-checks on libp2p-request-response
         run: cargo run semver-checks check-release --manifest-path="subject/protocols/request-response/Cargo.toml"
 
+  run-on-libp2p-uds:
+    # Run cargo-semver-checks on a crate that has dependencies in a custom target
+    # /~https://github.com/obi1kenobi/cargo-semver-checks/issues/369
+    name: Run cargo-semver-checks on libp2p-uds 0.37.0
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout cargo-semver-checks
+        uses: actions/checkout@v3
+        with:
+          persist-credentials: false
+
+      - name: Checkout rust-libp2p
+        uses: actions/checkout@v3
+        with:
+          persist-credentials: false
+          repository: 'libp2p/rust-libp2p'
+          ref: '5b4eab7bafe6cba8fea6c806027ea680662b7cc6'
+          path: 'subject'
+
+      - name: Install rust
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          override: true
+
+      # rust-libp2p requires protobuf-compiler.
+      - name: Install protobuf-compiler
+        run: sudo apt install protobuf-compiler
+
+      - uses: Swatinem/rust-cache@v2
+        with:
+          key: libp2p-gossipsub-request-response
+
+      - name: Run semver-checks on libp2p-uds
+        run: cargo run semver-checks check-release --manifest-path="subject/transports/uds/Cargo.toml"
+
   run-on-core-graphics:
     # Run cargo-semver-checks on a crate with no semver violations,
     # to make sure there are no false-positives.

src/rustdoc_gen.rs

@@ -48,13 +48,21 @@ impl<'a> CrateSource<'a> {
                 .filter_map(|dep| dep.is_optional().then_some(dep.name()))
                 .map(|x| x.to_string())
                 .collect(),
-            Self::ManifestPath { manifest } => manifest
-                .parsed
-                .dependencies
-                .iter()
-                .filter_map(|(name, dep)| dep.optional().then_some(name))
-                .map(|x| x.to_string())
-                .collect(),
+            Self::ManifestPath { manifest } => {
+                let mut dependencies = manifest.parsed.dependencies.clone();
+                for target in manifest.parsed.target.values() {
+                    // Fixes /~https://github.com/obi1kenobi/cargo-semver-checks/issues/369
+                    // This part is not relevant to `Self::Registry`, because
+                    // it doesn't have a `target` field and doesn't differentiate dependencies
+                    // between different targets.
+                    dependencies.extend(target.dependencies.clone().into_iter());
+                }
+                dependencies
+                    .iter()
+                    .filter_map(|(name, dep)| dep.optional().then_some(name))
+                    .map(|x| x.to_string())
+                    .collect()
+            }
         };
 
         let feature_defns: Vec<&String> = match self {

test_crates/target-specific-dependencies/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+publish = false
+name = "target-specific-dependencies"
+version = "0.1.0"
+edition = "2021"
+
+[target.none.dependencies]
+async-std = { version = "1.6.2", optional = true }

test_crates/target-specific-dependencies/src/main.rs

@@ -0,0 +1,7 @@
+fn main() {
+    // This crate checks whether the tool correctly detects
+    // implicit features defined by target-specific dependencies.
+    // /~https://github.com/obi1kenobi/cargo-semver-checks/issues/369
+    #[cfg(not(feature = "async-std"))]
+    panic!("the tool should have built the project with this flag");
+}

tests/detects_target_dependencies.rs

@@ -0,0 +1,13 @@
+use assert_cmd::Command;
+
+#[test]
+fn detects_target_dependencies() {
+    // This test checks whether the tool correctly detects
+    // implicit features defined by target-specific dependencies.
+    // /~https://github.com/obi1kenobi/cargo-semver-checks/issues/369
+    let mut cmd = Command::cargo_bin("cargo-semver-checks").unwrap();
+    cmd.current_dir("test_crates/target-specific-dependencies")
+        .args(["semver-checks", "check-release", "--baseline-root=."])
+        .assert()
+        .success();
+}